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Subject: Re: [PATCH v2 2/3] iommu/tegra-smmu: Rework .probe_device and
 .attach_dev
To:     Nicolin Chen <nicoleotsuka@gmail.com>
Cc:     thierry.reding@gmail.com, joro@8bytes.org, krzk@kernel.org,
        vdumpa@nvidia.com, jonathanh@nvidia.com,
        linux-tegra@vger.kernel.org, iommu@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
References: <20200930003013.31289-1-nicoleotsuka@gmail.com>
 <20200930003013.31289-3-nicoleotsuka@gmail.com>
 <03710107-b6ad-5256-4550-09c610d0fded@gmail.com>
 <20200930053930.GD31821@Asurada-Nvidia>
From:   Dmitry Osipenko <digetx@gmail.com>
Message-ID: <e5b9f269-3ddd-d4e5-de26-413414c3ccf2@gmail.com>
Date:   Wed, 30 Sep 2020 08:48:49 +0300
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30.09.2020 08:39, Nicolin Chen пишет:
> On Wed, Sep 30, 2020 at 08:24:02AM +0300, Dmitry Osipenko wrote:
>> 30.09.2020 03:30, Nicolin Chen пишет:
>>> +	/*
>>> +	 * IOMMU core allows -ENODEV return to carry on. So bypass any call
>>> +	 * from bus_set_iommu() during tegra_smmu_probe(), as a device will
>>> +	 * call in again via of_iommu_configure when fwspec is prepared.
>>> +	 */
>>> +	if (!mc->smmu || !fwspec || fwspec->ops != &tegra_smmu_ops)
>>>  		return ERR_PTR(-ENODEV);
>>
>> The !mc->smmu can't be true.
> 
> Are you sure? I have removed the "mc->smmu = smmu" in probe() with
> this change. So the only time "mc->smmu == !NULL" is after probe()
> of SMMU driver is returned. As my comments says, tegra_smmu_probe()
> calls in this function via bus_set_iommu(), so mc->smmu can be NULL
> in this case.
> 

I missed that.